None.
This invention relates generally to dust collection and removal systems and relates in particular to a dust collection and removal system to be used in conjunction with apparatus for improving tire uniformity during the manufacture of tires.
Tire uniformity machines are well known in the art and the grinding of tires on such machines is also well known. Representative examples of tire uniformity machines may be seen in Beebe U.S. Pat. No. 4,805,125 and Cargould U.S. Pat. No. 5,029,467.
As part of the overall testing and inspection conducted on such machines, it is common to grind rubber from selected areas on the tire perimeter to bring the tire within the range of acceptable specifications. This is usually accomplished by advancing grinding stones into and out of contact with the tire. This operation is repeated until the high spots or non-specification peaks on the tire are eliminated and the tire is brought into the specified range.
A variety of sensors, non-contact probes and encoders are utilized with such machines for the purpose of locating areas of non-uniformity and also for properly positioning the grinders relative to the tire.
As a result of the grinding process, a great deal of dust is created. This resultant dust presents a number of problems in the tire inspection process. Dust is scattered throughout the operating area of the machine and frequently into the surrounding area. Accumulation of dust in the operating area of the machine tends to inhibit the operation of the requisite sensors, probes and encoders as these devices become covered and/or clogged by dust. Similarly, a portion of the dust resettles on the tire itself even becoming embedded in the tread thereof. This accumulation on the tire further inhibits operation of sensors, probes and encoders by interfering with the sensors"" ability to accurately detect the true surface of the tire. Further, the resultant dust presents an environmental hazard particularly for workers in close proximity to the machine.
Consequently, efforts have been made in recent years to devise methods and systems for removing and collecting the dust created by such machines. The prior art is replete with methods for removing dust and detritus from work areas generally, such as during woodworking or machining operations.
An example of such a method and device is seen in Iversen U.S. Pat. No. 5,594,972 which discloses a system employing a funnel assembly mounted in proximity to a workpiece. The funnel assembly is provided with a vacuum assist in the form of a vacuum hose affixed to the funnel. Dust, sparks, and grindings enter the funnel and pass therethrough into the vacuum hose which transports the material to a disposal point such as a collection container.
The primary disadvantage of using such passive methods and devices with tire grinding machines is that the fine rubber dust produced is initially at a relatively high temperature due to the frictional grinding process. As a result, the dust becomes sticky and tends to adhere both to itself and to the tire surface. As the hot rubber dust begins to cool, it adheres even more securely to the tire. This phenomenon makes a purely vacuum-based system impractical inasmuch as the typical vacuum developed by such systems is insufficient to dislodge the rubber dust adhered to the tire surface. Accordingly, only a portion of dust is removed.
One effort to overcome the disadvantages of the aforementioned method is shown in Healy et al. U.S. Pat. No. 4,279,076 which discloses a dust collection apparatus specifically tailored for use with tire grinding machinery. The disclosed device comprises a brush which contacts the tire surface in the proximity of the grinding wheel. The brush includes a plurality of apertures interspersed within the bristles. These apertures communicate with a vacuum assist by way of a hollow arm upon which the brush is mounted. Accordingly, the brush acts to dislodge dust adhered to the tire surface which, ideally, is then removed via the vacuum.
In use, the aforementioned device may present a number of practical disadvantages in removing dust during tire grinding. Because the brush must contact the tire in order to be effective, it is located such that it is subject to damage in the event of a mischuck of the tire. Further, constant contact with the tire causes a great deal of wear, necessitating periodic replacement of the brush in order to be effective. It has also been found that the brush bristles do not always reach fully into deep treads. Consequently, a portion of dust is left unremoved having been pushed even deeper into the tread. Another disadvantage is that the vacuum apertures interspersed among the bristles of the brush tend to become clogged necessitating periodic cleaning or replacement. Since virtually all vehicle tires are now subject to processing in these machines on a continuous assembly line basis, any downtime is obviously undesirable in addition to the expense of replacing the brushes themselves.
It is, therefore, thought desirable to provide a means for removing and collecting dust resulting from the grinding of tires, which does not require contact with the tire, thereby eliminating the brush and its attendant disadvantages.
It is, therefore, a principal object of this invention to provide a dust removal and collection system which is effective to dislodge and remove the majority of dust produced during the tire grinding process from the tire surface and surrounding area without contacting the tire itself.
To that end, it has been found that a nozzle emitting a pulsed air blast can be provided on existing tire grinding machinery, in the proximity of the grinding wheels, to effectively dislodge dust adhered to the tire surface, even that which has become embedded in the tread of the tire.
It has also been found that a vacuum assist may be provided in conjunction with the aforementioned nozzle to remove and carry away the dislodged dust from the area of tire grinding. Further, it has been found that the aforementioned nozzle may be provided with means for adjustment so as to allow the pulsed air blast to be directed to a particular location, thereby optimizing removal and collection of dust particles.